Dirigible mining auger



May 29, 1962 H, D. LETTs DIRIGIBLE MINING AUGER 4 Sheets-Sheet 1 FiledMarch lO, 1961 K WOI- W wm m, www M5, 5 V/ r/ l 1%/ f M m l mum mw v gIl 4 w H A/ 7%/ W//J/ w ww w NM w\ .nul .mbk NN `\\1 MM. NJN .hull li. lHw l l l l n ww Sw m? NE, l .IC wm N y w f o I LmlFlili!nuIIIMMNII-:---WI- N \\.N| *Ubi am mw May 29, 1962 H. D. LETTs3,036,821

DIRIGIBLE MINING AUGER Filed March l0, 1961 4 Sheets-Sheet 2 FVG. 2.

1 N VEN TOR. H4602@ .0. 4 1f-77S,

H D.L.ETTS

DIRIGIBLE MINING AUGER May 29, 1962 Filed March l0, 1961 4 Sheets-Sheet3 MMM May 29, 1962 H. D. LETTS DIRIGIBLE MINING AUGER 4 Sheets-Sheet 4Filed March l0, 1.961

INVENTOR i ,Lmeaz 0. 5771s United Stat This invention relates to adirigible mining auger.

An object of the present invention is to provide a dirigible miningauger which is operable from the outside of a hole being bored toposition the boring head for boring in the desired direction.

Another object of the present invention is to provide a dirigible miningauger which, during operation in a hole being bored, may be shifted to aposition in which the boring head will bore in a straight direction, inan upwardly direction, or in a downwardly direction.

A further object of the present invention is to provide a dirigiblemining auger which lends itself to ready assembly in a hole being bored.

A still further object of the present invention is to provide adirigible mining auger which is highly efficient in action, andcommercially feasible.

Other objects and advantages will become apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIGURES l and 1A represent a plan view of the dirigible mining augerassembly according to thefpresent invention in working position within ahole being bored in a coal vein;

FIGURE 2 is an enlarged view, with parts broken away and in section,taken on the line 2-2 of FIGURE l;

FIGURE 3 is a plan View, with parts broken away, and in section, takenon the line 3-3 of FIGURE 2;

FIGURE 4 is a side elevational view, partly in section, of the trailingend portion of the auger shaft of the mining auger assembly according tothe present invention;

FIGURE 4A is a side elevational 'sectional View of the leading endportion of the auger shaft and boring head of the mining auger assemblyaccording to the present invention in position in which the boring headwill bore in a straight direction;

FIGURE 5 is a sectional view taken on the line 5 5 of FIGURE 4A;

FIGURE 6 is a side elevational sectional view of the leading end portionof the auger shaft and boring head adapted so that the boring head willbore in an upwardly direction;

FIGURE 7 is a side elevational sectional view of the auger shaft showingthe end portion and boring head of FIGURE 6, but shifted so that theboring head will bore in a downwardly direction; p

FIGURE 8 is an end view, on a reduced scale, taken on the Iline 8 8 ofFIGURE 4A; and

IFIGURE 9 is an end view, on a reduced scale, taken on the line 9 9 ofFIGURE 4.

Referring to FIGURES 1 and 1A of the drawings, the numeral 20 generallydesignates a supporting frame, the frame including a pair oflaterally-spaced rear posts 2 and a pair of laterally-spaced front posts22. The frame comprises longitudinal side members 23 extending betweenand secured to the posts 21 and 22. A carriage 25 is slidably mounted onthe side lmembers 23 and carries a motor 26 whose shaft 27 isoperatively connected to a transmission 28, the transmission having adriven shaft 29 projecting therefrom. The end of the driven shaft 29 hasa hexagonal socket 30 which is attached to a hollow auger shaft 32,FIGURES l, 2 and 3.

The hollow auger shaft 32, FIGURES l and 1A, includes a trailing endportion 33 and a leading end portion 34 which is flexibly connected tothe trailing end portion 33 for movement with the latter. The rear endof the trailing end portion 33 of the auger shaft 32 is atet drivinglyconnected to the socket 30 of the driven shaft 29 by means of acouplingmember 3S. The coupling member 35 has a hexagonal socket 36 onone end, FIG- URES 2 and 3, which loosely receives a hexagonal portion37 provided on the rearward end of the auger shaft trailing end portion33, and has a hexagonal part 38 on the other end which is received inand embraced by the socket 30.

As shown in FIGURES 1 and 1A,.4 and 4A, the trailing end portion 33 ofthe auger shaft 32 includes two sections 33a and 33h arranged inconfronting end-to-end relation, the confronting ends being connectedtogether by a coupling 4l which permits lateral play, The coupling 41,FIGURE 4, comprises a tube 42 which has an end portion xedly supportedin the confronting end of the section 3311, and has the other endportion extending loosely into a sleeve 43 -xedly supported in theconfronting end of the section 33a, the other end portion of the tube 42being held in position within the sleeve 43 by means of a coupling pin44 which releasably seats in registering holes 45 and 45 provided in thesleeve 43 and the other end portion of the tube 42 respectively. Thecoupling pin is releasably held in coupling position by means of aspring-biased latch bar 44 supported upon the top of the section 33a ofthe trai-ling end portion 33 of the auger shaft 32, the latch bar havinga free end portion so shaped as to receive and detachably engage atapered flange 43 on the pin 44, as clearly shown in FIGURE 4. It is tobe noted that the sleeve 43 carries a conveyor flight 46 which matchesthe conveyor flights 47 on the sections 33a and 33h of the trailing endportion 33 of the auger shaft 32.

Flexible coupling means indicated generally by the numeral 50 connectsthe rear end of the leading end portion 34 of the auger shaft 32 to thefront end of the trailing end portion 33 of the auger shaft 32 or thenonconfronting end of the section 3'3b of the trailing end portion 33 ofthe auger shaft 32. Specically, the cou-V pling means comprises, FIGURES4, 4A, 6, 7, a female coupling member 51 which is txedly supported inthe non-confronting end of the section 33b of the trailing end portion33 of the auger shaft 32, the female member being provided on its innerface with teeth 52. A male coupling member 53 is ixedly supported in therear end of the leading end portion 34 of the auger shaft 32, the malemember being provided with external teeth. A locking split ring 55 isslipped over the teeth 54 until it drops behind'the teeth 54 andsurrounds the adjacent portion of the male member 53. 'Ihe male couplingmember carrying the ring S5 is then inserted into the female member 51until the free end of the male member 53 abuts the shoulder 51 on thefemale member 5l,

whereupon a two-part semicircular flange 51 is disposed so as tosurround the male member 53 adjacent the open end of the female memberSi, the ange being ixedly secured to the female member 5l as by weldingto there by hold the male member 53 in interlocking relation with thefemale member 51. The female member 5l carries a conveyor flight 56which matches the conveyor llights 4'7 on the sections 33a and 3311 ofthe trailing end portion 33 of the auger shaft 32, and also conveyorights 57 on the leading end portion 34 of the auger shaft 32.

Circumposed about and connected to the front end part 0f the auger shaftleading end portion 34 is a boring head 60 which is provided at equallyspaced intervals with cutter teeth 61. rllhe front end of the leadingend portion 34 of the auger shaft 32 terminates in a conical spiralcutter point 62 having rows of cutting teeth 63 along opposite sidesthereof.

A plurality of hollow tubular spokes 65, FIGURES lA, 4A, 6, 7, 8, aredisposed radially about the leading end portion 34 of the auger shaft 32inwardly of and adjacent the cutter head 60, the inner ends of thespokes 65 being ixedly secured to the leading end portion 34. A stem 66,FIGURE 8, is slidably supported in each of the spokes 65 and has aninner end which is within the leading end portion 34 of the auger shaft32 and has an outer end which is exteriorly of the outer end of theadjacent spoke 65. A shoe 67 is on the outer end of each of the stems66. A coil spring 68 is operatively connected to each stem 66 forbiasing the stems toward the conical members 70 mounted within leadingend portion 34 of the auger shaft 32, only one of the stems 66 havingthe coil spring operatively connected thereto being shown in FIGURES 6and 7.

The cam embodying an elongated conical member 70 is mounted within theleading end portion 34 of the auger shaft 32 for longitudinalforward-and-backward movement. The conical member 70 is free to rotatewith the auger shaft 32 although it is mounted within the leadingportion 34 of the auger shaft for longitudinal movement relative to theauger shaft. The conical member 70 is normally disposed so that theintermediate part extends slidably between and engages the inner ends ofthe stems 66 and has a base 71 on the side of the spokes 65 remote fromthe boring head 60 and has the apex 72 on the side of the spokes 65adjacent the boring head 60, the position of FIGURE 4A, and the one inwhich the boring head 60 will bore in a straight direction. The conicalmember 70, when normally disposed, projects each of the shoes 67 againstthe action of the respective springs 68 when each of the shoes is in thelowermost position, to engage the wall of the auger hole 75, FIGURE 4A,to thereby fix and steer the boring head 60 so as to bore in a straightdirection. Projecting longitudinally from the apex 72 of the conicalmember 70 is a bar 76 which is slidably supported in a fixed collar 77disposed within the leading end portion 34 of the auger shaft 32inwardly of and adjacent the cutter point 62. It is to be noted that thebase 71 of the conical member 70 slidably engages the leading endportion 34 of the auger shaft 32, and this sliding engagement of thebase 71 with the leading end portion 34 and of the bar 76 with thecollar 77 constitutes the mounting of the conical member 70 forlongitudinal forward-and-backward movement within the leading endportion 34 of the auger shaft 32.

By virtue of the contour of the conical member 70, the shoes 67 areprojected equally and cannot be extended to a radius of more thanone-half (1/2) of the diameter of the auger hole 75. The projected shoes67 exert a steering function, and such function depends upon therelationship of the position of the projected shoes, and the diametersof the boring head 60 or auger hole, and of the trailing end portion 33of the auger shaft 32.

It is preferred that the trailing end portion 33 of the auger shaft 32be provided with eccentric non-rotating guide spiders, each of saidspiders being indicated by the numeral 80 with a spider 80 being appliedto the section 33b of the trailing end portion 33 inwardly of andadjacent the flexible coupling means 50 and another spider 80 beingapplied to the section 33a of the trailing end porion 33 inwardly of andadjacent the coupling 41, as shown in FIGURES 1A and 4. The purpose ofthese guide spiders is to keep the rearward portion of the boring head60 on the vertical center line of the hole 75 being bored and maintainan angle of incidence in a vertical direction. Each spider 80, FIGURE 9,includes a hub 81 which is circumposed about and rotatably supported ona bearing 81 seated in a retainer ring 81 which encompasses and iswelded to the adjacent part of rthe section 33a of the trailing endportion 33 adjacent the confronting end of the aforesaid section, andradially disposed about the hub 81 and fixed thereto are a plurality ofrigid spokes, two of the spokes being of like size and indicated by thenumeral 82, and the other of the spokes being indicated by the numeral83 and being longer than the two spokes 82. The spider is so disposedthat the two shorter spokes 82 engage opposite points of the Wall of4the lower half of the auger hole 75, and the longer spoke 83 engagesthe point of the wall in the upper half of the auger hole 75.

An actuator 85 is disposed within the auger shaft 32 and has one endoperatively connected to the base 71 of the conical member 70 and hasthe other end exteriorly of the rear end of the trailing end portion 33of the auger shaft 32. Means or a slide 40 is mounted for reciprocatorymovement on the intermediate part of the coupling member 35, and saidslide is operatively connected to the other end of the actuator, theslide, upon execution of its reciprocatory movement, effecting theforward-and-back- Ward movements of the conical member 70. Specifically,the actuator 85, FIGURES l, 2, 3, 4 and 4A, comprises a push member 86having one end operatively connected to the base 71 of the conicalmember 70 and a plurality of rods 87 arranged in free end-to-endabutting relation are positioned on the side opposite the push member 86and have the end of the adjacent rod bearing freely against the otherend of the push member 86, the free end portion of the foremost rod 87extending exteriorly of the rear end of the rear end portion 33 of theauger shaft 32 with the free end of the hindmost rod 87 being attachedto the slide 40 by means of a bar 88. The bar 88 is supported in abearing 88 which encompasses and is slidable along the coupling member35. A coil spring 89 is operatively connected to the push rod 86, suchspring effecting the backward movement of the conical member 70. Theslide 40, as shown in FIGURE 3, is rollably supported by rollers 46a onthe side members 23 of the supporting frame.

A pair of hydraulic cylinder asemblies 90 and 91, FIG- URE 3, are'operatively connected to the slide 40, and actuation of the piston rods92 and 93 respectively of said assemblies effects the reciprocatorymovement of the slide 40 and consequent forward-and-backward movement ofthe conical member 70. To effect the forward stroke of the slide 40,with the auger shaft 32 being rotated by the driven shaft 29 and thecarriage 25 advancing, uid under pressure is admitted through the line95 to the assemblies -96 and 91, resulting in the piston rods 92 and 93moving in a forwardly direction and simultaneously therewith theexecution of the forward stroke of the slide 40 `and of the forwardmovement of the conical member 70. When it is desired to effect therearward stroke of the slide 40, with Vthe auger shaft 32 being rotatedby the driven shaft 29 and the carriage advancing, uid under pressure isadmitted through the line 96 to the asemblies 90 and v91, resulting inthe piston rods 92 and 93 moving in a rearwardly direction andsimultaneously therewith the execution of the rearward stroke of theslide 40 and of the rearward movement of the conical member 70.

In operation, with the auger shaft assembly in position within the augerhole 75 and the boring head in position to bore in the hole in astraight direction, the auger shaft 32 is caused to rotate by means ofthe driven shaft 29 and as the auger shaft projects the boring in astraight direction in the hole 75 the carriage 25 is caused to advanceas the projected boring progresses.

Should it be desired to project the boring in an upwardly direction inthe auger hole 75, while the auger shaft 32 is being rotated by thedriven shaft 29 and the carriage 25 is advancing, fluid under pressureis admitted through the line 95 to the cylinder assemblies 90` and 91,resulting in the piston rods 92 and 93 moving in a forwardly directionand simultaneously therewith the execution of the forward stroke of theslide 40 and of the forward movement of the conical member 70. Theexecution of the forward movement of the conical member 70 projects theshoes 67 equally and when each shoe is in the lowermost position toengage the wall of the auger hole 75 to thereby ix and steer the boringhead 60 so as to project the boring in an upwardly direction, as shownin lFIGURE 6.

When it is found desirable to project boring in a downwardly directionin the auger hole 75, while the auger shaft 32 is being rotated by thedriven shaft 29 and the carriage 25 is advancing, fluid under pressureis admitted through the line 96 to the cylinder assemblies l90 and 91,resulting in the piston rods `92 and 93 moving in a backwardly directionand simultaneously therewith the execution of the backward stroke of theslide 40, the coil spring `89 causing the conical member 70 to executeits backward movement. The execution of the backward movement 0f theconical member 70 projects the shoes 67 equally and when each shoe is inthe lowermost position to engage the wall of the auger hole 7S tothereby fix and steer the boring head 60 so as to project the boring ina downwardly direction, as shown in FIGURE 7.

Although the trailing end portion 33 of the auger shaft 32 is shown anddescribed as comprising two sections 33a and 33h, it is to be understoodthat the section 33b could comprise a substantial number of sections,for example, 2O to 30 sections like section 31317, of from l0 to 20-feet in length, so that lthe auger shaft 32 could project the boring inthe auger hole 75 to a depth of from 200 to 400 feet, or more.

What is claimed is:

l. In a mining auger, a hollow auger shaft including a trailing endportion and a leading end portion flexibly connected to the trailing endportion for movement with the latter, means on the rearward end of saidtrailing end portion for attachment to la driven shaft to impartrotational movement to said auger shaft, a boring head connected to thefront end part of said auger shaft leading end portion for rotation withthe latter-named portion, a plurality of spokes disposed radially aboutsaid auger shaft leading end portion inwardly of and adjacent saidcutter head and having inner ends `fixed to said auger shaft leading endportion and having outer ends, a stem slidably supported in each of saidspokes and having an inner end within said auger shaft leading endportion and having an outer end exteriorly of the outer end of theadjacent spoke, a shoe on the outer end of each of said stems, a camembodying an elongated conical member mounted within said auger shaftleading end portion for longitudinal forward-and-backward movement, aneccentric non-rotatable guide spider on the auger shaft trailing endportion for maintaining the angle of incidence in a vertical direction,said conical member being normally disposed so that the intermediatepart extends slidably between and engages the inner ends of said stemsand has the base on the side of said spokes remote from said boring headand has the apex on the side of said spokes adjacent said boring head,said conical member when normally disposed projecting the shoes to aposition to engage the walls of an auger hole and tix and steer theboring head so as to bore in a straight direction, an actuator disposedwithin said auger shaft and having one end operatively connected to thebase of said conical member and having the other end exteriorly of therear end of said auger shaft trailing end portion, spring meansoperatively connected to each of said stems for biasing the adjacentshoe toward said conical member, and means operatively connected to theother end of said actuator for effecting the forWard-and-backwardmovement of said conical member, said conical member upon execution ofits forward movement from the normal position projecting the shoes to aposition to engage the wall of an auger hole and x and steer the boringhead so as to bore in an upwardly direction and upon execution of itsbackward movement from the normal position permitting the shoes underthe action of the springs associated with the stems to be retracted to aposition to engage the wall of an auger hole and fix and steer theboring head so as to bore in a downwardly direction.

2. In a mining auger, a hollow auger shaft including a trailing endportion and a leading end portion flexibly connected to the trailing endportion for movement with the latter, means on the rearward end of saidtrailing end portion for attachment to a driven shaft to impartrotational movement to said auger shaft, a boring head connected to thefront end part of said auger shaft leading end portion for rotation withthe latter-named portion, a plurality of spokes disposed radially aboutsaid auger shaft leading end portion inwardly of and adjacent saidcutter head and having inner ends fixed to said auger shaft leading endportion and having outer ends, a stem slidably supported in each of saidspokes and having an inner end within said auger shaft leading endportion and having an outer end exteriorly of the outer end of theadjacent spoke, a shoe on the outer end of each of said stems, a camembodying an elongated conical member mounted within said auger shaftleading end portion for longitudinal forward-and-backward movement, aneccentric non-rotatable guide spider on the auger shaft trailingend'portion for maintaining the angle of incidence in a verticaldirection, said conical member being normally disposed so that theintermediate part extends slidably between and engages the inner ends ofsaid stems and has the base on the side of said spokes remote from saidboring head and has the apex on the side of said spokes adjacent saidboring head, said conical member when normally disposed projecting theshoes to a position to engage the walls of an auger hole and fix andsteer the boring head so as to bore in a straight direction, an actuatordisposed within said auger shaft and having one end operativelyconnected to the base of said conical member and having the other endexteriorly of the :rear end of said auger shaft trailing end portion,spring means operatively connected to each of said stems for biasing theadjacent shoe toward said conical member, means operatively connected tothe other end of said actuator for effecting the forward movement ofsaid conical member, and spring means operatively connected to saidactuator for effecting the backward movement of said conical member,said conical member upon execution of its forward movement from thenormal position projecting the shoes to a position to engage the wall ofan auger hole and tix and steer the boring head so as to bore in anupwardly direction and upon execution of its backward movement from thenormal position permitting the shoes under the action of the springsassociated with the stems to be retracted to a position to engage thewall of an auger hole and fix and steer the boring head so as to bore ina downwardly direction.

3. In a mining auger, a hollow auger shaft including a trailing endportion and a leading end portion flexibly connected to said trailingend portion for movement with the latter, means on the rearward end ofsaid trailing end portion for attachment to a driven shaft to impartrotational movement to said auger shaft, a boring head connected to thefront end part of said auger shaft leading end portion for rotation withthe latter-named portion, a plurality of spokes disposed radially aboutsaid auger shaft leading end portion inwardly of and adjacent saidcutter head and having inner ends fixed to said auger shaft leading endportion and having outer ends, a stem slidably supported in each of saidspokes and having an inner end within said auger shaft leading endportion and having an outer end exteriorly of the outer end of theadjacent spoke, a shoe on the outer end of each of said stems, a camembodying an elongated conical member mounted within said auger shaftleading end portion for longitudinal forward-and-backward movement, aneccentric non-rotatable guide spider on the auger shaft trailing endportion for maintaining the angle of incidence in a vertical direction,said conical member being normally disposed so that the intermediatepant extends slidably between and engages the inner ends of said stemsand has the base on the side of said spokes remote from said boring headand has the apex on the side of said spokes adjacent said boring head,the conical member when normally disposed projecting the shoes to aposition to engage the wall of an auger hole and x and steer the boringhead so as to bore in a straight direction, an actuator disposed withinsaid auger shaft, said actuator embodying a push rod having one endoperatively connected to the base of said conical member and a pluralityof rods arranged in free end-to-end abutting relation positioned on theside opposite said push rod and having the end of the adjacent rodbearing freely against the other end of said push rod and having thefree end portion of the hindmost rod exteriorly of the rear end of saidauger shaft rear end portion, a reciprocatory slide operativelyconnected to the free end of the hindmost rod for effecting the forwardmovement of said conical member, spring means operatively connected toeach of said stems for biasing1 the adjacent shoe toward said conicalmember, and spring means operatively connected to said push rod foreffecting the backward movement of said conical member, said conicalmember upon execution of its forward movement from the normal positionprojecting the shoes to a position to engage the wall of an auger holeand fix and steer the boring head so as to bore in an upwardly directionand upon execution of its backward movement from the normal positionpermittin-g the shoes under the action of the springs associated withthe stems to be retracted to a position to engage the wall of an augerhole and fix and steer the boring head so as to bore in a downwardlydirection.

4. In a mining auger, a hollow auger shaft including a trailing endportion and a leading end portion arranged forwardly of said trailingend portion and having the rear end in end-to-end relation with respectto the forward end of said trailing end portion, flexible coupling meansconnecting the rear end of said leading end portion to the forward endof said trailing end portion, means on the rearward end of said trailingend portion for attachment to a driven shaft to impart rotationalmovement to said auger shaft, a boring head connected to the front endpart of said auger shaft leading end portion for rotation with thelatter-named portion, a plurality of spokes disposed radially about saidauger shaft leading end portion inwardly of and adjacent said cutterhead and having inner ends fixed to said auger shaft leading end portionand having outer ends, a stem slidably supported in each of said spokesand having an inner end within said auger shaft leading end portion andhaving an outer end exteriorly of the outer end of the adjacent spoke, ashoe on the outer end of each of said stems, a cam embodying anelongated conical member mounted within said auger shaft `leading endportion for longitudinal forward-and-backward movement, an eccentricnon-rotatable guide spider on the auger shaft trailing end portion formaintaining the angle of incidence in a vertical direction, said conicalmember being normally `disposed so that the intermediate part extendsslidably between and engages the inner ends of said stems and has thebase on the side of said spokes remote from said boring head and has theapex on the side of said spokes adjacent said boring head, said conicalmember when normally disposed projecting the shoes to a position toengage the wall of an auger hole and x and steer the boring head so asto bore in a straight direction, an actuator disposed within said augershaft and having one end operatively connected to the base of saidconical member and having the other end exteriorly of the rear end ofsaid auger shaft trailing end portion, spring means operativelyconnected to each of said stems for biasing the adjacent shoe towardsaid conical member, and means operatively connected to the other end ofsaid actuator for effecting the forward-and-backward movement of saidconical member, said conical member upon execution of its forwardmovement from the normal position projecting the shoes to a position toiengage the wall of an auger hole and fix and steer the boring head so asto bore in an upwardly direction and upon execution of its vbackwardmovement from the normal position permitting the shoes under the actionof the springs associated with the stems to be retracted to a positionto engage the wall of an auger hole and fix and steer the boring head soas to bore in a downwardly direction.

5. Ina mining auger, a hollow auger shaft including a trailing endportion and a leading end portion arranged forwardly of said trailingend portion and having the rear end in end-to-end relation with respectto the forward end of said trailing end portion, exible coupling meansconnecting the rear end of said leading end portion to the forward endof said trailing end portion, means on the rearward end of said trailingend portion for attachment to a driven shaft to impart rotationalmovement to said auger shaft, a boring head connected to the front partof said auger shaft leading end portion for rotation with thelatter-named portion, a plurality of spokes disposed radially about saidauger shaft leading end portion inwardly of and adjacent said cutterhead and having inner ends xed to said auger Shaft leading end portionand having outer ends, a stem slidably supported in each of said spokesand having an inner end within said auger shaft leading end portion andhaving an outer end exteriorly of the outerj end of the adjacent spoke,a shoe on the outer end of each of said stems, a cam embodying anelongated conical member mounted within said auger shaft leading endportion for longitudinal forward-and-backward movement, said conicalmemiber being normally disposed so that the intermediate part extendsslidably between and engages the inner ends of said stems and has thebase on the side of said spokes remote from said boring head and has theapex on the side of said spokes adjacent said boring head, an eccentricnon-rotatable guide spider on the auger shaft trailing end portion formaintaining the angle of incidence in a vertical direction, said conicalmember when normally disposed projecting the shoes to a position toengage the wall o-f an auger hole and fix and steer the boring head soas to bore in a straight direction, an actuator disposed within saidauger shaft, said actuator embodying a push rod having one endoperatively connected to the base of said conical member and a pluralityof rods arranged in free end-to-end abutting relation positioned on theside opposite to said push rod and having the end of the adjacent rodbearing freely against the other end o-f said push rod and having thefree end portion of the hindmost rod exteriorly of the rear end of saidauger shaft rear end portion, a reciprocatory slide operativelyconnected to the free end of the hindmost rod for effecting the forwardmovement of said conical member, spring means operatively connected toeach of said stems for biasing the adjacent shoe toward said conicalmember, and spring means operatively connected to said push rod foreffecting the backward movement of said conical member, said conicalmember upon execution of its forward movement from the normal positionprojecting the shoes to a position to engage the wall of an auger holeand fix and steer the boring head so as to -bore in an yupwardlydirection and upon execution of its backward movement from the normalposition permitting the shoes under the action of the springs associatedwith the stems to be retracted to a position to engage the wall of anauger hole and x and steer the boring head so as to bore in a downwardlydirection.

References Cited in the file of this patent UNITED STATES PATENTS2,715,526 Letts Aug, 16, 1955

